I have a colleague that cannot receive external mail? I have checked the settings and as far as I know, everything is fine! She sent herself an email from her gmail account and she got the following text..
"----- The following addresses had permanent fatal errors -----
(reason: 553 5.3.0 <firstname.lastname@example.org>... No such user here)
----- Transcript of session follows -----
... while talking to smtp.ourdomain.co.uk.:
<<< 553 5.3.0 <email@example.com>... No such user here
550 5.1.1 <firstname.lastname@example.org>... User unknown
Final-Recipient: RFC822; email@example.com
Remote-MTA: DNS; smtp.ourdomain.co.uk
Diagnostic-Code: SMTP; 553 5.3.0 <firstname.lastname@example.org>... No such user here
Last-Attempt-Date: Fri, 9 Apr 2010 13:26:20 +0100"
Do you guys need the actual domain name and user name present? If so I will post them again.